US 2010/0165056 A1Published application

Heater Stack In A Micro-Fluid Ejection Device And Method For Forming Floating Electrical Heater Element In The Heater Stack

AssigneeLexmark International, Inc.

InventorsYimin Guan, Zachary Justin Reitmeier, Carl Edmond Sullivan

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Abstract

A method for forming a floating heater element includes processing a silicon substrate to form a heater stack having the heater element on the substrate with peripheral edge portions, processing the heater stack by depositing and patterning a layer of photoresist or hard mask thereon to substantially mask the heater stack and form a trench through the photoresist or hard mask exposing a surface area of the substrate extending along the peripheral edge portions of the heater element, and processing the masked heater stack and exposed surface area of the substrate by sequentially removing the photoresist and portions of the substrate at the exposed surface area and that underlie the heater element so as to create a well in the substrate undercutting the heater element and open along the peripheral edge portions thereof, the well being capable of filling with a fluid so as to produce the floating heater element.

Claims20

Dependent claims

A method for forming a floating electrical heater element in a micro-fluid ejection device, comprising:

processing a silicon substrate to form an electrical heater stack of a micro-fluid ejection device having an electrical heater element formed on the silicon substrate, the electrical heater element having peripheral edge portions extending at anisotropically etchable orientations relative to the silicon substrate and a mask overlying the electrical heater stack to form a trench through the mask that exposes an area of a first surface of the silicon substrate which extends along the peripheral edge portions of the electrical heater element;
and
processing the masked electrical heater stack and exposed first surface area of the silicon substrate by anisotropically etching sequentially the portions of the silicon substrate at the exposed first surface area thereof and that underlie the electrical heater element so as to create a well in the silicon substrate undercutting the electrical heater element and open along the peripheral edge portions of the electrical heater element, the well capable of filling with a fluid so as to produce, in effect, a floating electrical heater element on the silicon substrate of the electrical heater stack.

A heater stack in a micro-fluid ejection device, comprising:

a silicon substrate;
a heater substrata of resistive and conductive layers on a front side of said silicon substrate supporting and forming an electrical fluid heater element having peripheral edge portions;
an anisotropically etched well formed in said silicon substrate undercutting said electrical heater element and open along said peripheral edge portions of said electrical heater element, said well capable of filling with a fluid so as to produce, in effect, a floating electrical heater element on said silicon substrate of said electrical heater stack;
and
a via form through said silicon substrate to said well therein underneath said electrical heater element having a sidewall extending from a back side of said silicon substrate toward said front side thereof and to said well underneath said heater element for centrally supplying the fluid into a bottom of said well spaced beneath said heater element.

2 more elements

Dependencies are inferred from the claim text.